Nano Architectured Binder-Free Metal Oxide Electrodes for High Voltage Supercapacitor

Supercapacitor as an energy storage device is gaining attention as its energy density is almost nearing the batteries. As the supercapacitor already has exceptional properties such as safety, high power density and long cycle stability, the main drawback of low energy density must be tackled by the scientific community. The energy density of the supercapacitor device is largely determined by the factors such as specific capacitance and working voltage of the supercapacitor device as it is directly proportional to them. The high specific capacitance can be achieved from transition metal oxides with excellent electrochemical properties such as manganese oxide and molybdenum oxide and assembling them in asymmetric combination would deliver a high working voltage of the device. Working voltage window is also dependent on the work function difference between the anode and cathode. The prime focus of this work involved selecting the right metal oxide material as anode and cathode with high work function difference providing a higher voltage (> 2V), thus delivering a high energy density. Also, nanostructuring the metal oxides is done to obtain a very high specific surface area. The electrodes are synthesized by a facile, direct growth electrodeposition process eliminating the need for dead binders used typically. The electrodes synthesized are characterized by X-ray diffraction, scanning electron microscopy and Raman spectroscopy. Asymmetric supercapacitor is fabricated and tested by electrochemical impedance spectroscopy, cyclic voltammetry, and galvanostatic charge-discharge measurements.